Multiple spindle boring mechanism



Feb. 6, 1940. 1 A EDEN I 2,188,941

MULTIPLE SPINDLE BORING MECHANISM Filed March 23, 1938 2 sheets-Shen 1 INVENTOR.

BY .IMES EDE/v.

@ff j ATTORNEY.

Feb. 6, 1940.

J. A. EDEN 2,188,941

MULTIPLE SPINDLE BORING MECHANISM 2 Sheets-Sheet 2 Filed March 23, 1958 yd@ @d @311/ 1N VENT OR.

1/wss EDEN.

ATTORNEY.

,Patented Feb. s, 1940 UNITED STATES Artur orties MULTIPLE; SPINDLE Bonino ivmcnANisM AJames A. Eden, Springfield, Mass., assigner to Baush Machine Tool Company,

Springfield,

Mass., a corporation of Massachusetts 1 Application ylinders and similararticles are bored by the use of a vsingle cutting tool mounted on a boring bar in such 'manner that its cutting edge or poi-nt movesY in ahelical path of very gradual pitch until it reaches the end oiy the cylinder or other opening to be bored, thereupon the bar with lits A, cutting tool is withdrawn upwardly through the bore. If the cutting tool were merely drawn upwardly without being moved4 out of its cutting position, it would yscore the completed bore in its yupper passage. y y To avoid this scoringit` is Acustomary to shift theworkpiece, such as the cylinder, relative to the cutting bar so'th'at the cutting point or edge is spaced slightly inwardly ofthe surface of the completed bore, whereupon the boring bar may be movedup-l Wardly without danger of scoring the surface of the bore.

When a 'number of cylinders are bored simultaneously Ain a multiple boring machine', it is necessary 'that the cutting points or tools for all ofthe several bores must point in one direction so that the workpiecek may be moved or shifted .slightly in `this direction to clear the cutting points. For it will be obvious that if certain of the points or cutting elements extend in a direction opposite to lthat of ythe others, a shifting of the workpiece in a direction to clear one point would move it still :further into the path of the other and aggravate the scoring action.

In apparatus heretofore used lit has been necessary, therefore, to have all of the cuttingele'- ments point in the same direction or to bein the same phase for each cuttingv bar.

During theboring each cutter exerts a pres- -sure against the workpiece. When a number of bores are being made on a single workpiece as, for "example, a multi-cylinder enginev and all of the cutters are in the same relative position, the totalthrust or push thus' exerted is a p sumof all of thethrusts of the individual cutters.

To secure the workpiece against' displacement under these concentrated thrusts is difficult in lview of the practice or necessity to make the workA piece as light as Apossible and, therefore, readily distortable so that the tightness to which it can be.l vclamped is limited. Also tolerance is, in many cases, very small, amounting in the case 3 Claims.

March 23, 193s, sensi No. 197,543

of cylinder blocks to less than a thousandth of an inch.

, My present invention avoids, or overcomes, v'the various diihculties mentioned above and provides multiple boring ymechanisn'i whereby the cutters may be disposed at complementary positions or anglesv one to the other so as to balance the side thrust of the cutters during boring and upon the completion of the boring action may bebrought to thesame relative position or angle so as to clear the bore upon appropriately shift.

ing the workpiece. l

The various features of my invention are illustrated by way of example in the accompanying drawings in which Fig. l is a vertical elevation or front view of a multiplespindle boring machine embodying my invention, a six-spindle machine being illustrated by way of example. Fig. 2 is a vertical 'section through a coupling embodying afpreierred form of the invention. Fig. 3 is a diagrammatic sketch showing the positions of the cutters during the boring. Fig. 4 is av similar sketch showing the position of the cutters after boring hut before the workpiece is shifted. Fig. 5 .is a view similar to Fig. '4 but with the workpiece shifted `to clear the cutter points. Fig. 6 Vis a horizontal section taken on line't-G of l'lig. 2 showing thev position of certain coupling elements in driving or boring position. 'Fig 7 is a View similar to Fig. 6 showing the cutting bar in a different relative position to the driving element.

In my invention, I provide couplings between certain of .the driving spindles and the' cutter bars which engagev and drive the cutter bars from the spindles ata complementary angle, vfor example, about l degrees from they position of other cutter bars during the boring 'operation but which. permit the boring bar to swing forwardly into the same position, or in phase with the other cutting v`parsor cutting elements upon the completion of the boring.` For this purpose certain of (the coupling elements are provided with a driver having engaging or driving` surfaces positioned diametrically opposite' the axis of rotation when the cutting bar is' to be heid 180 degrees from the position of an adjacent cutting bar. These driving faces, which be part of the driving teeth, provide a clear space` through which the driven element, which may also comprise a pair of teeth, may swing when the driving elements are stopped. Accordingly, during the boring the driving element acts against the driven element with the cutter acting in the opposite direction from an 'adjacent -or the above coupling will be in the position shown` ing drawings, the invention is shown applied to' a machine having a bed IS on which a workpiece l l may be mounted for boring, and a vertically movable head I 2 from which depend a number of spindles or cutting bars I3. Any number of spindles may be employed, six being shown by way of example, for boring a six-cylinder engine block. Power may be transmitted to the cutting bars i3 from a main drive shaft Hl through any suitable mechanism in the head l2. The cutting bars I3 are guided immediately above the workpiece Il by a suitable guiding element l5. Certain of the cutting bars i3, depending upon the number of bars and the arrangement of the couplings, are coupled directly or rigidly to the driving elements, others have a coupling arrangement as shown in Figs. 2 to 7 inclusive.v

In this arrangement a drive spindle I6, driven by any suitable mechanism from the main drive shaft lll, has splined to its lower end a driving element or driver Il. This driver ll may be secured to the spindle It by such screw or other suitable means to prevent vit from falling therefrom.

As shown more particularly in Fig. 6, the driver Il is provided with a pair of diametrically opposite teeth i8. Encircling the driver Il is a coupling i9 Ahaving a pair of diametrically oppositely pointing or opposed teeth 2BA positioned to be engaged and driven by the teeth i8. The coupling i9 extends below the level of the driver il and is hollow to receive a stem 2l extending upwardly from the upper end of a cutter bar 22. The stem 2l projects upwardly througha gear tooth 23 which is secured in the lower part of the coupling I9 by means of a set screw 24 which may be inserted between any of a pair of gears of the gear wheel 23 to enable the position of thecutter bar 22 to be adjusted to any angle relative to the coupling I9.

The cutter bar 22 is held resiliently upwardly against the gear 23 by means of a spring 25 conned between the upper face ofthe gear 23 and a` nut 26 on the upper part of the stem 2l. AThe cutter bar 22 carries a cutter 21 at its cutting' end. The arrangement of the various elements 23, 25 is shown merely conventionally, not being a part of the present invention.

During the boring, operation the elements of in Fig. 6, the direction of rotation being as kshown by the arrow and with the teeth i8 of the drive ll acting against the teeth 20. If every alternate boring bar or tool is provided with such a coupling, whereas the others are provided with a direct rigid coupling, the boring teeth 2l during the boring operation may be in the position shown in Fig. 3.

that the result of these various thrusts is approximately zero.

When the boring tool has completed the boring operation and has moved through the workpiece -to the position shown in Fig. 2, the driving spindle apply- I'is stopped byy cutting off the power and ing the brake.

As the coupling and the boring bars are nowf` free to move under their momentum, they `may swing as indicated by the arrow at the lower part of Fig. 6 to the position shown in Fig. 7 in which the teeth 29 have rotated approximately 180 degrecs until stopped by the contact with the opposite faces of Athe teeth i8.l The several cutters will then be in the position shown in Fig. 4; that is, all pointing in one direction as, for eXample,-to the right. The workpiece may now be shifted slightly to the right, that is from the position shown in dotted lines in Fig. 5 to that shown in full lines, which will leave a clearance between the cutting edge of thecutters and the completed bores of the workpiece. The workpiece may thereupon be lowered without any danger of scoring the bore by the relatively upwardmovement of the cutters.

It will be apparent that instead of havingthe cutters point diametrically opposite, they might be at dierent complementary angles in which there would be a balance between more than two 13 y cutters. For example, three cutters` might be balanced at angles of degrees.

there would be a driving toothy i8 and an addi- In such casa;

` tional stopping tooth placedat an appropriatey angle or" 120 degrees: Similarly, other angles could be'employed with-'other combinations of cutting tools.

Also it will be understood that other means` than the momentum of the cutter tools may be employed for ycarrying them from the position-fof Fig. 6. In restarting the work it will be under-H stood that the `couplings will bel returned to the position of Fig. 6 before reboring another work-1'" piece. v Through the above invention I haveI providedr a very simple and effective coupling whereby certain cutters in a multiple cutting or boring machine may be arranged at complementary'thrust angles during-boring andbe brought to alignment',

before removal from'the workpiece.

Various modifications maybe made vby those,v

skilled in the artwithout departing fromtheinvention as defined in the appended claims.

What I claim is:

1. In a multiple spindle fmachine, a driving: spindle, a driven tool bar and a coupling between,

said spindle and saidr bar, said couplingcompris.- ing a driver mounted on said spindle and having'a pair of diametrically positioned driving teeth,;a

hollow coupling secured to the tool bar and ex-l tending upwardly to enclose said driver'and having diametrically positioned teethl engaging the"y teeth of said driver, said coupling being free to rotate in advance of said driver until Aits teeth engage the opposite sides of the drivingteethin; v

i. n 4 egg; 2. In a multiple spindle machine, a driving u advance.

spindle, a driven tool bar and a coupling rbetween i" said spindle and said bar, said coupling'comprising a driver mounted on said spindle and havingl f symmetrically positioneddriving teeth, a hollow coupling to drive the tool bar and extending upp wardly to enclose saiddriver and having symg metfcally positioned teeth corresponding to and engaging those of said driver, said coupling being free to rotate in advance o'f said driver until their;

teeth engage theopposite ysides ofthe teeth in advance.

ing teeth engaging and driving'those of said coupling when the cutting element of the respective tool bar is complementary in thrust to that of adjacent tool bars, said coupling being rotatable in advance of said driving teeth sufciently to bring its cutter elements in phase With that of the directly coupled tool bar.

JAMES A. EDEN. 

